Randomized trial shows morning influenza vaccination improves immune responses in adults aged 60-85, suggesting optimal timing could enhance protection.
Key Points
This research aims to assess how the timing of influenza vaccination impacts immune responses in older adults.
Data from the Chrono-Vax randomized controlled trial was analyzed.
Antibody titers and T-cell responses were measured before and one month after vaccination.
Participants were aged 60-85 years and received the vaccine between 9:00 and 17:00.
Morning vaccination (9:00-11:40) resulted in a greater fold increase in antibody titers compared to afternoon timings (p = 0.005 for early and p = 0.009 for late).
A significant effect of vaccination timing on antibody responses was found (p = 0.012), with peak effectiveness at 9:00.
Influenza-specific T-cell responses showed a similar trend but did not reach statistical significance.